Fiber optic hydrogen sensor resisting temperature interference

The principle of an extrinsic Fabry-Perot interferometric (EFPI) optical fiber hydrogen sensor is introduced in the paper. In order to carry out the mathematic model of the relationship between the change of Fabry-Perot gap length and hydrogen concentration, the stress transfer model of the sensor is analyzed. Two channels temperature compensation method is used to avoid the interference caused by the variation of the environmental temperature, so the stability of the system is enhanced. The validity of theory has been proved by means of investigating the responsibility of the sensor in a function of the hydrogen concentration, and the analytic data was close to the experiment results.The feasibility of the sensor has been validated by the temperature experiment.